Bump ion-java from 1.9.3 to 1.9.4

Bumps [ion-java](https://github.com/amzn/ion-java) from 1.9.3 to 1.9.4.
- [Release notes](https://github.com/amzn/ion-java/releases)
- [Commits](amazon-ion/ion-java@v1.9.3...v1.9.4)

---
updated-dependencies:
- dependency-name: com.amazon.ion:ion-java
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

Signed-off-by: dependabot[bot] <[email protected]>

build.gradle

@@ -16,7 +16,7 @@ repositories {
 dependencies {
     implementation "org.jetbrains.kotlin:kotlin-stdlib-jdk8:1.6.20"
     implementation "org.jetbrains.kotlinx:kotlinx-serialization-core-jvm:1.3.2"
-    implementation "com.amazon.ion:ion-java:1.9.3"
+    implementation "com.amazon.ion:ion-java:1.9.4"
     testImplementation "io.kotest:kotest-runner-junit5:5.2.2"
     testImplementation "io.kotest:kotest-assertions-core:5.2.2"
 }